DENVER -- Clint Barmes homered and Yorvit Torrealba added a go-ahead two-run double in the sixth, leading the Colorado Rockies to a 4-3 win over slumping San Francisco on Monday night.

The Giants have now lost a season-high six straight games.

Jason Grilli (1-0) got two outs in the sixth to earn his first win as a member of the Rockies. Brian Fuentes pitched around an opening single in the ninth for his sixth save in eight chances.

Fred Lewis had two triples for San Francisco and Randy Winn hit a solo homer in the first to extend his hitting streak to 14 games. He also had a single and an RBI on a sacrifice fly.

Barmes led off the fourth with a solo homer to left, extending his hitting streak to 12 games. He now has four homers this season.

The Giants had something going in the eighth when Winn led off with a single and Benjie Molina drew a walk.

Aaron Rowand hit a slow roller to Garrett Atkins at third and he threw it over to Omar Quintanilla covering second, who took a solid shot from hard-sliding pinch runner Emmanuel Burriss but still got enough on the throw to complete the double play. Rich Aurilia then flew out to right.

Starter Pat Misch is still searching for that elusive first major league win. He's now pitched in 24 games, including eight starts, over the last three years without a victory to show for it.

Misch entered the sixth up 3-1, but the Rockies scored three times to send him to another no decision. Misch ended the night giving up three runs and five hits over 5 1-3 innings.

Vinnie Chulk (0-3) took the loss after walking Ryan Spilborghs and allowing Torrealba's two-run double down the left field line.

The Rockies inserted Atkins into the cleanup spot to take advantage of his prowess against lefties, and he responded with two hits, including an RBI single, off Misch.

He's now hitting .519 off southpaws this season.

Winn's homer was his second of the season, and came on an 81-mph changeup from starter Jorge De La Rosa.

Rockies righty Kip Wells said before the game that he thinks he can be back within a month after recently undergoing surgery to remove blood clots in his pitching hand.

The 31-year-old Wells had a three-inch scar on the inside of his upper right arm after Dr. Robert Thompson removed clots from his wrist by traveling down an artery with a wire during a four-hour procedure on May 6.

Wells was placed on the 15-day disabled list retroactive to April 29. He's hoping to begin playing catch next week.